Gas-blast circuit interrupter



March 18,1969

w. M. LEEDS GAS -BLAST CIRCUIT INTERRUPTER Filed July 28, 1965 SheetFIG. I.

March 18, 1969 w. M, LE D 3,433,913

GAS -BLAS T CIRCUIT INTERRUPTER United States Patent 3,433,913 GAS-BLASTCIRCUIT INTERRUPTER Winthrop M. Leeds, Forest Hills, Pittsburgh,Pa.,-assignor to Westinghouse Electric Corporation, Pittsburgh, Pa.,

a corporation of Pennsylvania l 7 Filed July 28, 1965, Ser. No. 475,440US. Cl. 200-148 Claims Int. Cl. H01h 33/82, 9/40, 33/14 ABSTRACT OF THEDISCLOSURE A gas-blast circuit interrupter is provided with a pair ofseparable main contacts shunted by the combmatron of a pair of separableimpedance contacts 1n ser es with a resistance. A single blast valveserves umtarlly as an upstream blast valve for controlling the gas flowat the main contacts, and at the same time, as a downstream blast valvefor controlling the gas flow at the separable impedance contacts. A timedelay is provided to separate the main contacts prior to separation ofthe separable impedance contacts.

This invention relates, generally, to gas-blast circuit interruptersand, more particularly, to gas-blast c1rcu1t interrupters adaptable forheavy-power duty A general object of the present invent1on 1s to providean improved compressed-gas circuit interrupter of simplifiedconstruction and capable of interrupting heavy-power circuits.

Another object of the present invention is to provide an improvedcompressed-gas circuit interrupter suitable for high-voltageapplication, and particularly adaptable. for operation using 7 ahighly-efiicient arcextinguishing gas, such as sulfur-hexafluoride (SPgas, and in which improved extinguishing efiectiveness is obtained.

Another object of the present invention is to provide an improvedcircuit interrupterhaving a pair of separable rnain contacts using anupstream blast valve, and an electrically-parallel shunting pair ofresistance con tacts using a downstream blast valve, in which the1mproved blast valve of the instant application unltarlly performs bothblast-valve functions.

Still a further object of the pesent invention 1s to provide an improvedcompressed-gas circuit interrupter of the rotating-arm type, in whichthe passage means for conducting gas through the one or "more hollowrotating arms provides, additionally, an exhaust passage for downstreamblast-valve action exerted on a shunting pair of resistance contacts. e

" Another object of the present invention is to provlde an improvedcompressed-gas circuit interrupter of the type set forth in UnitedStates patent application filed Feb. 26, 1965, Ser. No. 435,560, now US.Patent 3,371,176, issued Feb. 27, 1968 to Winthrop M. Leeds, entitledHigh-Voltage Circuit Interrupter With a Pair of Fluid-ConductingPivotally-Mounted Contact Arms, and assigned to the assignee of theinstant application. More particularly, it is a distinct purpose of thepresent invention to simplify the resistance-interrupting operation ofthe aforesaid patent rendering it more simple and of compactarrangement. l l

Still a further object of the present invention is to providean improvedcompressed-gas circuit interrupter 3,433,913 Patented lylar. 18, 1969ice modules is considerably increased to thereby cut down on the numberof modules for the higher-voltage applications.

Further objects and advantages will readily become apparent upon readingthe following specification, taken in-conjunction with the drawings, inwhich:

-' FIGURE 1 is a side elevational view of one pole-unit of a three-phasecircuit interrupting structure;

FIG. 2. is a diagrammatic view of the main and resistance contactstructure for one of the interrupting modules of the circuit interrupterillustrated in FIGURE 1, the contact structure-being shown in thepartially open-circuit position; 1

IFIG. 3 is an enlarged fragmentary view showing in more detail one ofthe arc-extinguishing units, the contact 'structure being illustrated inthe closed-circuit position; FIG. 4 is a plan view, in section, takensubstantially along the line IV-IV of FIG. 3 with the rotating arms,however, in longitudinal section, and also showing the blast-valveoperating mechanism;

FIG. 5 is a perspective view of the bridging resistance contactassemblage of thepresent invention;

FIG. 6 is a fragmentary enlarged detail view showing the lost-motionconnection between the main and resistance contacts; and,

--FIG. 7 isa-simplified diagrammatic view indicating the impedance, orresistance contacts, and their relationship with the main contactspresent in one of the interrupting-modules of the circuit-interruptingarrangement of FIG-URE'I.

Referring to the drawings, and more particularly to FIGUREl thereof, thereference numeral 10 generally designates a three-phasecircuit-interrupting assemblage. 1 only illustrates a side elevationalview of one of the pole-units of the three pole-units utilized in suchathree-phase operating arrangement. It is to be under stood that thereare, intact, three such pole-units in alignment, and FIGURE 1' onlyshows a side elevational view of one such pole-unit.

It will be observed that, generally, there are provided threeinterrupting modules 12, each of which is supported in"an upstandingmanner, as shown in FIGURE 1, by a hollow insulating supporting columnconstruction 14. With reference to FIG. 2, extending upwardly interiorlyof each hollow insulating supporting column construction 14 is ahigh-pressure supply pipe 16, which supplies highpressurearc-extinguishing gas to a high-pressure reservoir 18-, the latterdisposed interiorly of a live metallic lowpr'essure housing 20. K l

As illustrated'in FIG. 2, it will be observed that each metallicrelatively low-pressure housing 20 has extending therewithin a pair ofterminal bushings 22, to the interior ends of which are fixedly securedtubular relatively stationary contact structures 24. As shown in moredetail inPIG. 3 of the drawings, each tubular relatively stationarycontact 24 makes'contacting engagement with a plurality ofresiliently-biased finger contacts 26, the latter-being carried adjacentthe free extremities of a rotating-arm movable contact assemblage,generally designated by the reference numeral 30.

i In more detail, each rotatable movable contact assemblage 30 includesa pair of movable arc-extinguishing units 32., which direct gas flowobtained from a flow of high-pressure gas through the hollow interior30a of the rotating movable contact assemblage 30.

V With reference to FIG. 4 of the drawings, it will be noted that theinterior'30a of each movable rotatable contact assemblage 30 may, attimes, be communicated through a reciprocally-movable blast-valvestructure 40 tOa-higlrpressure region, generallydesignated by thereference numeral 50, and communicating through auxiliary upstreamorifice apertures 52 to the general interior 49 of the high-pressurereservoir tank 18. It will, therefore, be apparent that upon leftwardopening movement of the blast valve 40, apertures a will become alignedwith the openings 30b provided at the inner extremities of the rotatingmovable arms of the contact assemblage 30 and will provide an outwardlyflowing blast of gas through the hollow arm portions of the rotatingmovable assemblage 30; and this gas blast will be directed by theinsulating gas directing orifices in opposite directions through themovable tubular stationary contact 24 and also through the tubularmovable contact assemblage, generally designated by the referencenumeral 58, as shown in FIG. 3 of the drawings, although FIG. 3 showsthe closed-circuit position of the contact structure.

As shown in more detail in FIG. 3 of the drawings, each movable contactassemblage 58 comprises a movable tubular arc horn 58a and thesurrounding inwardlybiased resilient finger contacts 26, the lattermaking engagement with the external surfaces of the stationary contacts24.

With reference to FIG. 4 of the drawings, it will be noted that thehigh-pressure reservoir housing 18 in cludes an inwardly-projectingstrut 18a, which fixedly supports into position the tubular bearingsleeve 18b, the latter serving to support a movable resistance bridgingcontact assemblage, generally designated by the reference numeral inFIG. 5, and comprising a metallic rotatable bearing sleeve 62 having anoutwardly-jutting arm 64.

The arm 64 has an axially-extending nose portion 64a, which projectsinto a recess provided by a casting hub portion 72 constituting a partof the movable rotatable contact assemblage 30. Accordingly, there isprovided a lost-motion connection between the movement of the mainrotating hollow contact assemblage 30 and the sleeve-like movableresistance contact assemblage 60, as shown more clearly in FIG. 6 of thedrawings.

Generally, the operation of my improved modular type arc-extinguishingassemblage 12 is such as to effect release of the operating mechanism,the latter being disposed within a mechanism compartment (FIG. 1)disposed at the lower end of the framework 87 supporting each pole-unit10, and thereby permit counterclockwise opening rotative movement of themovable contact assemblage 30, as indicated by the arrows 31 in FIG. 2of the drawings. This will effect through a blast-valve operatingmechanism 33 (FIG 4) inward opening movement of the blast valve 40,thereby permitting a blast of gas to flow radially outwardly through thetwo passages 30a associated with the rotating movable contact assemblage30, as shown in FIG. 4. Extinction will occur at the main arcsestablished within the interrupting units 32, but the circuit will bemaintained through impedance, or resistance sections 90, which areelectrically connected between the inner ends of the terminal bushings22 and fixed resistance contacts 94, which are supported by insulatingbushings 96 extending through the side walls of the high-pressurereservoir 18, in a manner more clearly indicated in FIGS. 3 and 4 of thedrawings.

As a result of the foregoing construction, following takeup of the lostmotion 80, the rotatable bridging sleeve 62, carrying the movablebridging resistance contacts 98, will separate from the stationaryresistance contacts 94 and the orifice contacts 52 and draw a pair ofserially-related impedance, or resistance arcs 97 to be acted upon by aninwardly flow of compressed gas, as indicated by the arrows in FIG. 4.As shown in FIG. 4, the inner ends of the resistance arcs 97 terminateat arc-horn portions 97a supported by a T-shaped bracket 19.

Extinction of the resistance-current arcs 97 is thereby achieved by theextinguishing gas flow through the stationary orifice contacts 52 andcontinued rotative movement introduces two isolating gaps into thecircuit, as

well understood by those skilled in the art. To maintain the maximumangular displacement between the rotative movable contact assemblage 30and the rotatable supporting resistance bridging sleeve 62, there ispreferably provided a compression spring (FIG. 6) situated in thelost-motion cavity 70 provided in the hub portion 72 of the mainrotative movable contact assemblage 30. This biasing action, as suppliedby the compression spring 110, will insure that during the closingoperation the resistance contacts 94, 98 and 52 will close prior to theclosing of the main moving contacts 58 into engagement with the mainstationary contacts 24.

FIG. 7 diagrammatically illustrates the impedance, or resistance shuntsin a simplified manner. It will be obvious that the utilization of theresistance sections 90 will facilitate interruption at the main contacts24, 5'8, and will improve the power factor of the circuit therebyfacilitating subsequent interruption of the resistance arcs 97. Theextinguishment of the resistance arcs 97 (FIG. 7), which are drawnthrough the orifice openings 52 (FIG. 4) is thus a relatively easy task.Also, it will be noted that the movement of the reciprocally-operablemain blast valve 40 not only serves as a downstream blast valve for theresistance contacts 52, 94 but also as an upstream blast valve for theextinguishing action exerted on the main contacts 24, 58 associated witheach arc-extinguishing unit 32.

To effect proper opening motion of the blast valve 40, there is provideda linkage, which is similar to that set forth in the aforesaid patentapplication Ser. No. 435,560. As described in detail in the aforesaidpatent application, there is provided at the end of the reciprocallymovable blast valve 40 a generally conical portion 100 extendinginwardly to deflect gas through openings or ports 40a in the side wallof the valve 40. The valve 40 has a stem 40b which extends through aguide portion 400 on the outer end of the hollow bearing support 1 8d. Avalve spring 40c surrounding the valve stem 40b between the end 180 ofthe bearing support 18d and a washer 40d on the valve stem 40b biasesthe valve 40 to the closed position. A pin 40c retains the washer 40d onthe valve stem 400.

The valve 40 may be opened by a cam 43 rotatably mounted on a pin 44.The cam 43 has teeth 45 thereon engaged by a pawl 46 carried by an arm47 pivotally mounted on the pin 44. The arm 47 is actuated by a link 48which, in turn, is actuated by a bell-crank 49. The bellcrank 49 isrotated by an insulating operating rod 51 extending downwardlyinteriorly of the insulating hollow column 14 and pivotally connected tothe rotating assemblage 30 as shown in FIG. 3.

The pawl 46 is biased into engagement with the teeth 45 by a spring 53disposed between one end 46a of the pawl 46 and a projection 47a on thearm 47. When the link 48 is moved to the left, as shown in FIG. 4, thecam 43 is rotated counterclockwise to open the valve 40. At the end ofthe opening movement, the end 46a of the pawl 46 engages a pin 57 todisengage the pawl from the teeth 45, thereby permiting a spring "59 toreturn the cam 43 to the closed position. The valve spring 40b thenrecloses the valve 40. The arm 47 is returned to the nonactuatingposition when the breaker is reclosed.

From the foregoing description it will be apparent that there has beenprovided an improved compressed-gas circuit interrupter in which asingle blast valve 40 serves as an upstream blast valve for the mainarcing contacts, and also as a downstream blast valve for the shuntingresistance contacts. There results a simplified and compactconstruction. As used in the specification and also in the claims, avalve is designated as upstream or downstream with reference to acontact structure, if it is physically located (in the upstream case)between the high-pressure source and the contacts, or, alternatively (inthe downstream case), the contacts are 10- cated -between the blastvalve and the high-pressure source.f

t The present invention makes possible a 345 km, 25,000 mva.circuit-breaker rating in a single'colilmn of two main breaks for eachpole-unit, using shunting impedances, such as resistors and separateresidual current interrupters. With two'taller:columns and four mainbreaks the rating would be 700 kv,, 50,000, mva., while with three stilltaller columns and six main breaksthe .rating would be 1000 kv., 75,000mva. Moreover, and very importantly, such improved constructionis'lower-in cost than present commercial designstof this particulartype.

Although there has been illustratedand described a specific structure,it is to be clearly understood that the same was merely forthe purposeof illustration, and that changes and modifications may readily be madetherein by those skilled in the art-without departing from the spiritand scope of the invention.

I claim as my invention:

1. A gasblast type of circuit interrupter including a pair of separablemain arcing contacts, impedance means and serially-connected impedancearcing contacts disposed in shunting relationship to said pair ofseparable main arcing contacts, means defining a high-pressurereservoir, means for separating the main arcing contacts before theseparation of the impedance arcing contacts, and single blast-valvemeans for serving as an upstream blast valve for gas flow at the maincontacts and also as a downstream blast valve for gas flow at theimpedance contacts.

2. In combination, a high-pressure reservoir containing high-pressuregas under pressure and providing a hollow bearing support, at least ahollow rotary main contact arm pivotally mounted on said hollow bearingsupport and carrying a movable main arcing contact, a stationary mainarcing contact cooperable with the movable main arcing contact toestablish a main-current arc, a movable blast valve for controlling aflow of high-pressure gas through said hollow bearing support andthrough the hollow main contact arm to effect extinction of themaincurrent arc, a shunting impedance and separable impedance contacts,at least one of said impedance contacts being disposed interiorly ofsaid high-pressure reservoir, movable contact bridging means supportinga companion impedance contact and having a lost-motion connection withsaid hollow rotating main contact arm, and orifice contact meansdisposed in the hollow bearing support for providing a downstream blastof gas to extinguish the residual current are.

3. In combination, means defining a high-pressure reservoir containinghigh-pressure gas under pressure and providing a hollow bearing support,a rotating main contact assemblage pivotally mounted upon said hollowbearing support and having two hollow outwardly-extending movablecontact arms, each of said movable contact arms carrying a movable maincontact, a relatively stationary main contact cooperable with eachmovable main contact, a movable blast valve for controlling a flow ofhighpressure gas through said hollow bearing support and radiallyoutwardly through the two hollow contact arms to effect extinction ofthe two main current arcs, a shunting impedance and separable impedancecontacts associated with each main movable contact, at least one of theimpedance contacts of each set of impedance contacts being disposedinteriorly of said high-pressure reservo r, movable bridging contactmeans supporting a movable bridging impedance contact and having alost-motion connection with the main rotating contact arm, andstationary orifice contact means disposed in the hollow bearing supportfor providing a downstream blast of gas to extinguish the two residualcurrent arcs.

4. A compressed-gas type of circuit interrupter including a relativelylow-pressure metallic housing, a pair of terminal bushings extendinginteriorly within said housing and carrying a pair of relativelystationary main arcing contacts at the interior ends thereof, ahigh-pressure reservoir disposed within said housing and containinghighpressure gas under pressure and providing a hollow bearing support,a hollow rotating main contact-arm assemblage pivotally mounted on saidhollow bearing support and carrying a pair of movable main arcingcontacts at the outer extremities thereof, each main arcing contactbeing cooperable with a respective relatively stationary main arcingcontact, a movable blast valve for controlling a flow of high-pressuregas through said hollow bearing support and through theradially-outwardly extending hollow, main contact arms to effectextinction of the main current arcs, a resistance section disposedadjacent the interior end of each terminal bushing and having aresistance bushing connected therethrough extending interiorly withinthe high-pressure reservoir, a stationary impedance contact situated atthe interior end of each resistance bushing, a movable bridging contactsleeve carrying a pair of serially-related movable bridging contacts androtatable upon said hollow bearing support, means defining a lost-motionconnection between said movable bridging contact sleeve and the rotatingmain hollow contact assemblage, and stationary orifice contact meansdisposed in the hollow bearing support for providing a downstream blastof gas to extinguish the two residualcurrent arcs.

5. A gas-blast circuit interrupter including means defining ahigh-pressure gas reservoir, a pair of separable main arcing contacts, astationary impedance contact disposed within said high-pressure gasreservoir, impedance means connected between one of said separable maincontacts and said stationary impedance contact, gas blast conduit meansconnecting said reservoir with the space between the main arcingcontacts when separated, a blast valve located in said gas-blast conduitmeans and openable to provide a blast of high-pressure gas to extinguishthe main current are drawn between the separated main contacts, acooperating impedance contact spaced from said first-mentioned impedancecontact at least in the open position of the impedance contacts, meansfor establishing an impedance are between the two impedance contactssubsequent to the establishment of the main current are, saidsecond-mentioned impedance contact being so located in said gas-blastconduit means that opening of the blast valve will cause anextinguishing flow of high-pressure gas along said conduit -means whichwill in addition extinguish the impedance are.

6. A compressed-gas circuit interrupter including a high-pressure gasreservoir tank, a pair of terminal bushings extending into said tank andcarrying a pair of spaced impedance contacts at the inner ends thereof,two pairs of separable main arcing contacts, impedance means connectedbetween said interiorly-disposed stationary impedance contacts and oneof each pair of separable main contacts, gas-blast conduit meansconnecting said reservoir with the spaces between the two pairs of mainarcing contacts when separated, a single blast valve located in saidgas-blast conduit means and openable to provide a blast of high-pressuregas to extinguish the two seriallyrelated main current arcs drawnbetween the two pairs of separated main contacts, two stationary orificecontacts provided in said gas-blast conduit means, means forestablishing an impedance current arc between each stationary impedancecontact and its respective orifice impedance contact, means forestablishing said two impedance current arcs after the establishment ofthe two main current arcs, and the gas blast passing toward the maincurrent arcs in addition to passing through the two stationary orificeimpedance contacts to effect extinction of the two impedance currentarcs.

7. The combination as set forth in claim 6, wherein the gas-blastconduit means provides a hollow bearing portion, and the two movablemain arcing contacts are disposed at the free extremities of a rotatablecontact assemblage pivotally mounted upon said hollow bearing support.

8. The combination as set forth in claim 6, wherein the gas-blastconduit means provides a hollow bearing support for a movable rotatablecontact assemblage carrying a pair of movable main contacts, and theblast valve reciprocally operates within said hollow bearing support.

9. A compressed-gas circuit interrupter including a pair of separablemain arcing contacts, :means including an impedance and aserially-related pair of impedance contacts shunting said pair ofseparable main arcing contacts, means separating the pair of main arcingcontacts before the separation of the pair of impedance contacts,high-pressure gas-conducting conduit means interconnecting the regionadjacent the pair of impedance contacts with the region adjacent thepair of separable main arcing contacts, unitary blast-valve meansdisposed in said conduit means between the two pairs of contacts,whereby said unitary blast-valve means constitutes a downstream blastvalve for the impedance contacts and an upstream blast valve for themain arcing contacts.

10. The combination according to claim 9, wherein the unitaryblast-valve is a reciprocally operable sleeve valve operating axially ofthe gas-conducting conduit means.

References Cited UNITED STATES PATENTS 2,665,351 1/1954 Forwald.

2,977,446 3/ 1961 Baker.

3,014,111 12/ 1961 Forwald.

3,043,940 7/1962 Leeds.

3,093,717 6/ 19 63 Forwald.

3,291,947 12/ 1966 Van Sickle ROBERT S. MACON, Primary Examiner.

US. Cl. X.R.

